2012 shows how storm predictions can miss mark

Before packing up the family for a vacation to the Northeast last June, Al Sandrik double-checked the National Hurricane Center's predictions for Tropical Storm Debby.

It was headed for Texas, far enough away from his post in Jacksonville, where Sandrik works as a warning coordination meteorologist for the National Weather Service. He and his family sighed relief.

But Debby proved a downer.

A few days later, while staying in Washington, D.C., cable news told Sandrik that Debby had taken a turn for Florida, where it would soon bring harsh rain and winds and devastate hundreds of miles of beach, including in Sarasota and Manatee counties.

"I literally had to drop my family off at a family reunion in Jersey and came back to Florida," the scientist laments.

Sandrik's ill-fated vacation is not only a reminder of nature's irreverence for plans. It illustrates an emerging quandary for those preparing for disasters.

Thanks to scientific advancements, the public is benefiting from earlier warnings and more accurate predictions, with life- and property-saving consequences.

But when predictions are wrong, they can be way off the mark.

"I think what we're seeing is people get complacent because we're getting so good at the prediction," Sandrik said Monday.

"So when you get a storm like Debby, we're surprised."

Isaac, Sandy as case studies

Last year has proved an interesting case study among the meteorologists and emergency managers attending the Governor's Hurricane Conference this week in Fort Lauderdale.

Hurricane Isaac, which stalled the Republican National Convention in Tampa Last year, and so-called Superstorm Sandy, whose massive storm surge devastated much of the northeast, proved to be nightmares in their own way for forecasters. Each storm is different, and forecasters must balance myriad factors before they can warn coastal areas of where, when and how hard storms will hit.

In the end, it is a probability game.

Consider the case of Debby in late June. It was tracking toward Texas, as delineated by the cone diagram used ubiquitously by government agencies and television meteorologists.

On average, there is a 2/3 probability the storm would follow that track. That means there was a 1/3 chance Sandrik's vacation would be short-lived.

The disconnect between better predictions and better preparedness was especially evident in 2012.

As predictions go, 2012 was a good year — the NHC had a record-low margin of error after verifying track predictions against the actual path of storms.

"Two-thousand twelve was a successful year, no matter how you look at it," National Hurricane Center specialist John Cangialosi told conference attendees.

But calculating storm intensity proved less reliable, and when the models were off, the consequent devastation to unsuspecting coastal areas overshadowed any statistical victory.

"We do still make some occasional, big-time mistakes," he added. "There's no better way to see that than to look at last year."

Five-day forecast cone

Yet demand for more, better and earlier predictions is ravenous, especially ahead of this year one forecasters are predicting will be a "very active" hurricane season.

The National Hurricane Center is responding with new tools, including a five-day forecast they say will give emergency managers a better idea of which Atlantic disturbances will grow into tropical storms and hurricanes.

The extended forecast will complement the existing two-day forecast and will be rolled out this hurricane season, which begins June 1 and ends Nov. 30.

A preview of the forecast model was shown Monday in Fort Lauderdale, where more than 1,000 emergency managers and climate experts from 58 of Florida's 67 counties gathered for training.

Much like the cone that illustrates the track of a developing hurricane or storm headed for the U.S., the newest tool will illustrate a disturbance in the Atlantic with an "X." From that "X" a probability cone will stretch ahead to show where that tropical disturbance has, say, a 50 percent chance of developing into something more in the coming days.

The new five-day forecast has been quietly tested by National Hurricane Center forecasters over the past four years and has been deemed reliable enough for public release.

"This will give people more of a planning period," Cangialosi said, adding that the center noticed a gap between tropical storms and hurricanes that forecasters saw emerging in their statistical models and what they could confidently tell the public.

"Now we have sufficient study to successfully bridge that," he added. "We think this is very good."

The extended forecast comes as the hurricane center promises a new storm surge warning system akin to thunderstorm and tornado warnings, aimed at informing residents in threatened areas.

That new product is set to roll out in 2015 and is highly anticipated after the devastation wrought by storm surge in Isaac and Sandy in 2012.

Though forecasters are confident the five-day forecast will give an earlier heads-up for what could happen, there are concerns coastal residents will not know how to best use the information.

Some worry the tool's message could be lost on the public, which is already buffeted with wall-to-wall media coverage as storms approach. Add to that recent studies that have shown residents will seek out the forecast they want to hear when they are making the decision to evacuate or stay home.

The message, Cangialosi said, is to show probabilities, not certainties, so residents and emergency managers can have a little more time to prepare.

"One of the problems we're worried about is the public understanding probabilities," he said.

Never miss a story

Choose the plan that's right for you.
Digital access or digital and print delivery.